Knive sharpener



FIG. 1 is a top plan view of a knife sharpener showing my new design;

FIG. 2 is a right side elevational view thereof, the left side being the same in appearance as the right side;

FIG. 3 is a rear elevational view thereof;

FIG. 4 is a front elevational view thereof;

FIG. 5 is a bottom plan view thereof;

FIG. 6 is a sectional view thereof taken along line 6--6 of FIG. 2; and

FIG. 7 is a right, top perspective view thereof. 

The ornamental design for a knife sharpener, as shown and described. 